1. Field of the Invention
The present invention relates to a technique for manufacturing a semiconductor integrated circuit device having MISFETs (Metal Insulator Semiconductor Field Effect Transistors) and, more particularly, to a technique which is effective if applied to the manufacture of a semiconductor integrated circuit device having a DRAM (Dynamic Random Access Memory).
2. Background of the Invention
The LSI, represented by a large capacity DRAM of recent years, has encountered a serious problem in that the high cost of manufacture has been raised by an increase in the number of manufacturing steps, as the manufacturing process becomes more complicated with increases in integration, speed and function. In accordance with this, the number of insulating films and conductive films deposited over a semiconductor substrate at a temperature of 700 to 900.degree. C. has increased to make it difficult to achieve a high performance for the MISFETs by realizing a shallow junction. Moreover, the increase in the wiring resistance resulting from the miniaturization raises an obstruction to the speedup.